Analysis of the OH− binding energy in lithium niobate crystals

Abstract In this paper we present some new results on the behavior of OH centers in Mg doped lithium niobate samples in concentration just above the optical damage threshold. We studied how new hydrogen (protons) incorporate to the crystal distributing in different OH centers, and how some of these centers are preferentially destroyed when the hydrogen is extracted from the crystal. We conclude that in highly Mg doped LiNbO 3 crystals hydrogen tends to bound to oxygen ions located close to Mg Nb defects having a stronger binding energy than unperturbed OH centers. The energy difference is about 0.25 eV. When each Mg Nb defect has a close OH center, the remaining hydrogen forms unperturbed OH centers. Our results are compared with some recently published data.